Electric heating unit.



Fig.1.

Witnesses: 12 In Vent O1. 1

2 Tycho \/an fiHer,

Patented Sept. 27, 1910.

UNITED STATES PAT FIQE.

TYCHO VAN ALLER, 0F SCHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, .A CORPORATION OF NEW YORK.

' ELECTRIC HEATING UNIT.

Application filed July 23, 1908. Serial No. 444,908.

To all whom it may concern:

Be it known that I, TYcIIo VAN ALLER, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Electric Heating Units, of which the following is a specification.

This invention relates to electric heating devices and has for its object the provision of an electric heating unit in which the heat is uniformly and evenly distributed in a sim 1e and efficient manner.

One of the ob ects of my invention is to provide a unit, which may readily be adapted for heating various shaped surfaces, and.

'wliich may be applied to the part to be heated with a maximum of efficiency and simplicity.

In my previous application, Serial No. 432,023, I have described and claimed a unit which in a general way accomplishes the result above outlined. I have found, however, for many purposes that a unit which is thinner than the one which I have described in said application is preferable.

In carrying out my invention I form a unit of a resistance ribbon which is zig-zagged back and forth upon itself so as to form a continuous strip. This unit is preferably formed by winding the resistance conductor, which is covered with a thin film of insulation, into a closed helix and then flattening the helix upon itself. For this purpose I have found a resistance conductor, which when heated is coated with an insulating oxid, very suitable, although a conductor insulated in any suitable manner may be used. y

In the accompanying drawing, in which I have shown my invention embodied in concrete form, Figure 1 represents the outline of a flatiron with my flat unit applied thereto; Figs. 2, 3 and 4 represent the. various steps in the manufacture of the unit; Fig. 5 is an enlarged end view of the completed unit.

Referring to the drawing, 10 represents my unit formed into a flat resistance ribbon. This unit is mounted upon a fiatiron 11, preferably a short distance from the edge of the iron. I have found that by arranging this strip around the iron as shown that a very satisfactory distribution of the heat is obtained. This distribution is particularly edges are chiefly active on the work and the short distance for the heat to travel easily maintains the temperature. This unit 10 consists of a ribbon 12, which is made by first winding it around a core 13. The resistance ribbon may be of any suitable resistance material, preferably one which coats itself with an insulating oxid when heated. I have found that the wire disclosed in the application of Dempster, No. 400,691, is suitable for this purpose. The ribbon which may be of any desired width is wound upon the core as shown in Fig. 2 and the core is then removed as shown in Fig. 3. The wire may now be heated to form a coating of insulating oxid upon it by passing a current through it or it may be heated in any desired manner so as to roduce this result. The manner of obtaining this insulating coating upon the wire forms no part of my invention as any Suitable insulation which is thin and will stand the heat may be used. After the spiral is made in the form shown in Fig. 3 it is flattened on itself until the sides touch as shown in Fig. 4. This may be done by passing it through rollers or in any other desired manner. ductor is thus obtained which is substantially a wide resistance strip, but is of such a nature that it may be bent into any desired shape. The extreme thinness of the unit makes it possible to be placed in very intimate thermal relation with the part to be heated and will occupy very little space. The unit is produced at an extremely low cost and is very durable.

-While I have described my invention in connection with a specific material which is oxidized by heat, it should be understood that I do not limit my invention thereto except in so far as it is limited by the scope of the claims annexedhereto.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. A resistance unit comprising a helical conductor coated with a thin refractory in- A resistance conlatecl helical resistance ribbon flattened onto itself.

5., A resistance unit comprising an insulatecl resistance ribbon wound into it closed helix and flatteneol onto itself.

'6. A resistance unit comprising a resistance ribbon Wound into a helix and flattened onto itself and a terminal held Within the helix by engagement therewith.

7. A resistance unit comprising a resistonce ribbon Wound into 2t helix and flattened onto itself and a fiat terminal Within the helix and engaged on opposite sides thereby.

lln Witness whereof, I have hereunto set my hand. this 21st day of July, 1908.

BENJAMIN B. HULL, iETLEN @RFORD. 

